cnn international security analyst jim walsh is joining us with more on what's going on. one of the key questions, the weapons that they have, the weapons that eventually killed an m.i.t. police officer, seriously injured another local law enforcement officer. do we have any idea where they got those weapons? >> not yet. and i think that question also extends to the explosives, as well. but this is an investigation pursuing lots of lines of inquiry both foreign and domestic. i would have to guess, though, that rather than risk acquiring weapons and explosives from abroad, it's much more likely they were acquired domestically. >> these two guys apparently didn't have much money, but enough to buy explosives, pressure cookers, a rifle, long rifle according to the watertown police chief i spoke with. other weapons, as well. >> i'm sure they're already well into the suspect's computer files and financial records. we're getting a mixed picture because on the one hand, they seem to have had a modest style of living. on the other hand, there is that picture that's been widely ci